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Default values of C# types (C# reference)

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The following table shows the default values of C# types:

Type Default value
Any reference type null
Any built-in integral numeric type 0 (zero)
Any built-in floating-point numeric type 0 (zero)
bool false
char '\0' (U+0000)
enum The value produced by the expression (E)0, where E is the enum identifier.
struct The value produced by setting all value-type fields to their default values and all reference-type fields to null.
Any nullable value type An instance for which the HasValue property is false and the Value property is undefined. That default value is also known as the null value of a nullable value type.

Default value expressions

Use the default operator to produce the default value of a type, as the following example shows:

int a = default(int);

You can use the default literal to initialize a variable with the default value of its type:

int a = default;

Parameterless constructor of a value type

For a value type, the implicit parameterless constructor also produces the default value of the type, as the following example shows:

var n = new System.Numerics.Complex();
Console.WriteLine(n);  // output: (0, 0)

At run time, if the System.Type instance represents a value type, you can use the Activator.CreateInstance(Type) method to invoke the parameterless constructor to obtain the default value of the type.

Note

In C# 10 and later, a structure type (which is a value type) may have an explicit parameterless constructor that may produce a non-default value of the type. Thus, we recommend using the default operator or the default literal to produce the default value of a type.

C# language specification

For more information, see the following sections of the C# language specification:

See also